From: Vincent Mailhol > Sent: 02 December 2024 17:33 > > From: Vincent Mailhol <mailhol.vincent@xxxxxxxxxx> > > For completion, add statically_false() which is the equivalent of > statically_true() except that it will return true only if the input is > known to be false at compile time. This is pretty much pointless. It is just as easy to invert the condition at the call site. David > > The == operator is used instead of the ! negation to prevent a > -Wint-in-bool-context compiler warning when the argument is not a > boolean. For example: > > statically_false(var * 0) > > Signed-off-by: Vincent Mailhol <mailhol.vincent@xxxxxxxxxx> > --- > include/linux/compiler.h | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/include/linux/compiler.h b/include/linux/compiler.h > index 469a64dd6495fefab2c85ffc279568a657b72660..a2a56a50dd85227a4fdc62236a2710ca37c5ba52 100644 > --- a/include/linux/compiler.h > +++ b/include/linux/compiler.h > @@ -314,6 +314,7 @@ static inline void *offset_to_ptr(const int *off) > * values to determine that the condition is statically true. > */ > #define statically_true(x) (__builtin_constant_p(x) && (x)) > +#define statically_false(x) (__builtin_constant_p(x) && (x) == 0) > > /* > * This is needed in functions which generate the stack canary, see > > -- > 2.45.2 > > - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)
